1. Field of the Invention
The present invention relates generally to medical and surgical devices and systems that serve to remove air and fluids from the body of a patient after injury or during and after surgery. The present invention relates more specifically to a system for use in association with the removal of air and fluids from the chest cavity of a patient during surgery or as a manner of treatment for a chest injury.
2. Background Information
The human chest cavity is lined with membranes referred to as the parietal pleura and the visceral pleura. The parietal pleura line the chest cavity itself, while the viscera pleura are the membranes that line the lungs. The space between the two membranes is called the intrapleural space (or sometimes simply “the pleural space”) that normally has a small amount of fluid within it in a healthy individual. This fluid is drained and regulated by the lymphatic system and provides lubrication and cohesion between the pleura for normal lung function.
An individual may accumulate air, fluid, or purulent drainage in the intrapleural space due to a number of pathologic conditions. When blood accumulates in this space, the condition is referred to as a hemothorax; air accumulation in the space is referred to as a pneumothorax; and purulent drainage accumulating in that space is referred to as empyema. Under such conditions as these, chest tubes may be required to provide drainage of air and excess fluid of any type. Excess fluid in the intrapleural space may be caused by liver or kidney failure, congestive heart failure, infection, malignancy blocking the lymphatic system, trauma, or other injury to the lungs or chest cavity. If the amount of fluid is very small, chest tubes would not typically be necessary. However, if a considerable amount of fluid or blood that cannot be absorbed by the body itself is present, chest tubes and a drainage system will typically be required. Similar conditions may exist within the intrapleural space during and after surgical intervention into the chest cavity.
When there is an excess amount of fluid or air in the pleural space, simply having an open airway will not typically result in sufficient air exchange for the patient due to the likely presence of a partial or complete lung collapse. A lung collapse occurs when the pressure in the intrapleural space is altered by the excess air or fluid accumulation presses inward on the lung causing it to collapse. Normally, the intrapleural pressure is below atmospheric pressure, thus allowing the lung to easily expand. When a lung does collapse, chest tubes may be used to allow drainage of the air or fluid and restore normal pressure to the intrapleural space so the lungs can expand and adequate gas exchange will occur. Such chest tubes inserted into the pleural space are typically attached to a drainage system that is closed to the atmosphere and is often maintained at sub-atmospheric pressure so as to create suction.
Depending on the condition of the patient, a chest tube may be inserted and maintained at the patient's bedside, in an ambulance, or in an operating room. The positioning of a chest tubes and the point of insertion will depend in part upon the type of fluid which has accumulated in the intrapleural space.
Previous efforts to provide chest tube drainage systems have typically utilized gravity and suction to evacuate the excess fluids and air. The typical closed chest drainage system is maintained at a level lower than that of the patient in order for gravity to facilitate fluid drainage from the intrapleural space. Suction may also be used to promote the transfer of air or fluid out of the intrapleural cavity.
The traditional drainage system of the prior art involved the use of one, two, or three bottle pleural drainage systems. Each of these systems operated under the basic principles of gravity, positive pressure, and suction, with the one bottle system being the simplest, yet most difficult to monitor. The two bottle system required less vigilance with respect to fluid level monitoring, whereas the three bottle pleural drainage system enabled suction control. Most modern facilities now use a disposable (or partially disposable) pleural drainage system that combines suction control, fluid collection, and a water seal into one multi-chambered unit. These are simply three chambered systems that use the same principles as the classic three bottle system. Examples of such systems are described in U.S. Pat. Nos. 4,784,642, 4,769,019 and 4,354,493.
Several difficulties arise with systems heretofore described in the art, including the kinking of the tubing, the formation of clots and blockages, problems with the suction, and problems with dependent loops (air and fluid) in the tubing. Additionally, the classic bottle systems, even those that involve an integrated three chamber structure, are typically quite bulky and do not allow easy transportation or ambulation of the patient. Although some integrated systems have been developed that are directed to being lightweight, portable, non-breakable, and disposable, many problems with the collection tubing still exist. Additionally, these types of devices typically must be connected to large pump systems or stationary vacuum sources which decrease or altogether eliminate their portability.
A problem almost universally encountered within the prior art is the inadequate drainage of the intrapleural space due to clots or gelatinous inflammatory material and the resultant plugging or kinking of the tube. Another frequent problem in the prior art is the disposal of the biohazardous fluids from the drainage collection chambers. While the chambers may be sealed during use it is often necessary to expose the health care provider to the collected fluids during the removal and disposal process.